add websockets work

ktor/common/build.gradle

@@ -39,6 +39,8 @@ kotlin {
                 implementation kotlin('stdlib')
                 api "org.jetbrains.kotlinx:kotlinx-serialization-runtime-common:$kotlin_serialisation_runtime_version"
                 api "org.jetbrains.kotlinx:kotlinx-serialization-cbor-common:$kotlin_serialisation_runtime_version"
+
+                api projectByName("postssystem.utils.common")
             }
         }
         commonTest {

ktor/common/src/commonMain/kotlin/com/insanusmokrassar/postssystem/ktor/CorrectCloseException.kt

@@ -0,0 +1,3 @@
+package com.insanusmokrassar.postssystem.ktor
+
+object CorrectCloseException : Exception()

ktor/common/src/commonMain/kotlin/com/insanusmokrassar/postssystem/ktor/CorrectWebsocketUrl.kt

@@ -0,0 +1,14 @@
+package com.insanusmokrassar.postssystem.ktor
+
+private val schemaRegex = Regex("[^:]*//")
+
+val String.asCorrectWebSocketUrl: String
+    get() = if (startsWith("ws")) {
+        this
+    } else {
+        if (contains("://")) {
+            replace(schemaRegex, "ws://")
+        } else {
+            "ws://$this"
+        }
+    }

ktor/common/src/commonMain/kotlin/com/insanusmokrassar/postssystem/ktor/WebSockets.kt

@@ -0,0 +1,7 @@
+package com.insanusmokrassar.postssystem.ktor
+
+const val clientWebsocketHelloMessage = "Start getting of updates"
+const val serverWebsocketHelloMessage = "Accepted"
+
+const val serverWebsocketNewMessageMessage = "NewMessage"
+const val websocketFinalizationMessage = "Final"